Whole cell-SELEX of aptamers with a tyrosine-like side chain against live bacteriaElectronic supplementary information (ESI) available: Tables and figures presenting the selection conditions, the enrichment numbers, the sequencing data and the raw data for the selectivity and saturation binding assays. See DOI: 10.1039/c6ob02451c

In an effort to expand the binding and recognition capabilities of aptamers, a nucleoside triphosphate modified with a phenol that mimics the side chain of tyrosine was used in the selection of DNA aptamers against live bacteria. Of multiple modified aptamers that were isolated against Escherichia coli DH5α cells, one aptamer displays high selectivity and affinity for the target cells and is greatly enriched for phenol-modified dU nucleotides (dU y , 47.5%). When the same sequences are synthesized with TTP, no binding is observed. Taken together, these findings highlight the value of using modified nucleotide triphosphates in aptamer selections and portends success in SELEX against an array of whole cells as targets. A dUTP analog modified with a phenol that mimicks tyrosine was used in the selection of DNA aptamers against live bacteria, thereby expanding the binding and recognition capabilities of aptamers.